This disclosure generally relates to miter saws and, more particularly, to a leaning grid device for a miter saw.
Miter saws are currently used in various conditions for cutting a work piece. To this end, the operator may optionally move the saw blade to any of various positions or in any of various modes so as to perform a vertical cut, an angle cut, a bevel cut or a combined miter cut.
As will be appreciated, miter saws generally include a base, a worktable rotatably connected to the base, a leaning grid device or assembly (i.e., a fence assembly) for supporting a work piece, and a saw mechanism pivotally connected to the worktable. Common leaning grids generally have one of two forms, namely, a stationary leaning grid and a movable leaning grid.
The body portion and the functions of a stationary leaning grid are achieved by a single member.
A movable leaning grid generally includes a lower leaning grid fixed to the base and a movable upper leaning grid movably mounted to the lower leaning grid. The support surfaces of the lower and upper leaning grids of the movable leaning grid are in a same plane to function together as a support for the work piece. The leaning grid has a plane “A” for supporting the work piece. The plane “A” is required to be vertical to the working surface of the worktable and the plane “A” of the movable leaning grid is obtained and defined together by the finally adjusted support surfaces of the lower and upper leaning grids.
When performing a miter cut, the user may move the movable leaning grid towards the outer side of the miter saw so as to prevent the saw mechanism from interfering with the movable leaning grid. The upper leaning grid of known devices may thus be arranged as a movable leaning grid in various forms:
1. A special guide groove which is parallel to the support surfaces of the leaning grid is arranged between the upper and lower leaning grids and the interference resulting from a miter cutting operation of the miter saw may be avoided by moving the movable leaning grid along the guide groove;
2. The upper and lower leaning grids are hinged with each other where the movable leaning grid may rotate with respect to the stationary leaning grid with the axis of the rotational movement being vertical to the support surfaces of the leaning grids and the interference resulting from the miter cutting operation of the miter saw may be avoided by creating various positions after rotating the movable leaning grid;
3. The upper and lower leaning grids are hinged with each other where the upper leaning grid may rotate with regard to the stationary leaning grid with the axis of the rotational movement being vertical to the support surfaces of the leaning grids and the interference resulting from the miter cutting operation of the miter saw may be avoided by creating various positions after rotating the upper leaning grid; or
4. The upper leaning grid generally has at least two positioning posts with the lower leaning grid having a plurality of positioning holes where the directions of the axes of the posts and holes are parallel to the support surfaces and the interference resulting from the miter cutting operation of the miter saw may be avoided since the different cooperating positions of the posts with the positioning holes may create different positions of the upper leaning grid.
Since the lower leaning grid in such known devices is generally a stationary leaning grid, the miter saw still has some defects. For example, it is provided in the safety standard that the distance between the support surface of the leaning grid device and the saw blade should be as small as possible so as to prevent the work piece from flying out when cutting smaller work pieces. Considering the smaller distance between the stationary leaning grid and the saw blade which may result in the interference upon a miter cutting operation, the known leaning grid device cannot meet the requirements provided by the safety standard. In order to solve this problem, a U.S. Pat. No. 5,755,148 discloses an improved leaning grid device, which has a plate respectively added between the stationary leaning grids on two sides and the saw blade to fill the space between the stationary leaning grids and the saw blade. During miter cutting, the filled plate is removed. This solution, however, increases the number of the components and the manufacture cost, and complicates operation of the saw.